#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<unistd.h>
int main(int argc,char *argv[])
{
  if(argc!=4)
  {
    printf("Usage:\n\t%s -[add|sub|mul|div] x y\n\n",argv[0]);
    return 1;
  }
  int x=atoi(argv[2]);
  int y=atoi(argv[3]);
  if(strcmp("-add",argv[1])==0)
  {
    printf("%d+%d=%d\n",x,y,x+y);
  }
  else if (strcmp("-sub",argv[1])==0)
  {
    printf("%d-%d=%d\n",x,y,x-y);
  }
  else if (strcmp("-mul",argv[1])==0)
  {
    printf("%d*%d=%d\n",x,y,x*y);
  }
  else if (strcmp("-chu",argv[1])==0)
  {
    printf("%d/%d=%d\n",x,y,x/y);
  }
  else
  {
    printf("unKnown\n");
  }

}
